Red Hat Enterprise Linux (RHEL) and CentOS

Install the OS packages lvm2, iptables, sysstat, and net-tools by executing

sudo dnf install lvm2 iptables sysstat net-tools 

Remove docker and previously installed podman packages (if previously installed)

sudo dnf remove docker docker-ce podman podman-remote containerd.io

As a sudoers user, disable SELinux by adding the following parameter to /etc/selinux/config

SELINUX=disabled

Install podman version 4.2.*.

sudo dnf install podman-4.2.* podman-remote-4.2.*

If podman requires a proxy in your infrastructure setup, modify the /usr/share/containers/containers.conf file and add the HTTP_PROXY and HTTPS_PROXY environment variables in the [engine] section. Please note that multiple env variables in that configuration file exists — use the one in the [engine] section.

Example:

[engine]
env = ["HTTP_PROXY=http://{proxy-ip}:{proxy-port}", "HTTPS_PROXY=http://{proxy-ip}:{proxy-port}"]

Reload systemd configuration

sudo systemctl daemon-reload

Create OS groups, if they do not exist yet

Reference: Users and permissions

sudo groupadd elastic
sudo groupadd podman

Add user elastic to the podman group

Reference: Users and permissions

sudo useradd -g "elastic" -G "podman" elastic

As a sudoers user, add the following line to /etc/sudoers.d/99-ece-users

Reference: Users and permissions

elastic ALL=(ALL) NOPASSWD:ALL

Add the required options to the kernel boot arguments

sudo /sbin/grubby --update-kernel=ALL --args='cgroup_enable=memory cgroup.memory=nokmem swapaccount=1'

Create the directory

sudo mkdir -p /etc/systemd/system/podman.socket.d

As a sudoers user, create the file /etc/systemd/system/podman.socket.d/podman.conf with the following content. Set the correct ownership and permission.

File content:

[Socket]
ListenStream=
ListenStream=/var/run/docker.sock
SocketMode=770
SocketUser=elastic
SocketGroup=podman

File ownership and permission:

sudo chown root:root /etc/systemd/system/podman.socket.d/podman.conf
sudo chmod 0644 /etc/systemd/system/podman.socket.d/podman.conf

As a sudoers user, create the (text) file /usr/bin/docker with the following content. Verify that the regular double quotes in the text file are used (ASCII code Hex 22)

#!/bin/bash
podman-remote --url unix:///var/run/docker.sock "$@"

Set the file permissions on /usr/bin/docker

sudo chmod 0755 /usr/bin/docker

As a sudoers user, add the following two lines to section [storage] in the file /etc/containers/storage.conf. Verify that those parameters are only defined once. Either remove or comment out potentially existing parameters.

runroot = "/mnt/data/docker/runroot/"
graphroot = "/mnt/data/docker"

Enable podman so that itself and running containers start automatically after a reboot

sudo systemctl enable podman.service
sudo systemctl enable podman-restart.service

Enable the overlay kernel module (check Use the OverlayFS storage driver) that the Podman overlay storage driver uses (check Working with the Container Storage library and tools in Red Hat Enterprise Linux).

In Docker world there are two overlay drivers, overlay and overlay2, today most users use the overlay2 driver, so we just use that one, and called it overlay. Refer also to Use the OverlayFS storage driver.

echo "overlay" | sudo tee -a /etc/modules-load.d/overlay.conf

Format the additional data partition

sudo mkfs.xfs /dev/nvme1n1

Create the /mnt/data/ directory used as a mount point

sudo install -o elastic -g elastic -d -m 700 /mnt/data

As a sudoers user, modify the entry for the XFS volume in the /etc/fstab file to add pquota,prjquota. The default filesystem path used by Elastic Cloud Enterprise is /mnt/data.

/dev/nvme1n1	/mnt/data	xfs	defaults,nofail,x-systemd.automount,prjquota,pquota  0 2

Restart the local-fs target

sudo systemctl daemon-reload
sudo systemctl restart local-fs.target

Set the permissions on the newly mounted device

ls /mnt/data
sudo chown elastic:elastic /mnt/data

Create the /mnt/data/docker directory for the Docker service storage

sudo install -o elastic -g elastic -d -m 700 /mnt/data/docker

Disable the firewalld service. The service is not compatible with Podman and interferes with the installation of ECE. You must disable firewalld before installing or reinstalling ECE.

sudo systemctl disable firewalld

Configure kernel parameters

cat <<EOF | sudo tee -a /etc/sysctl.conf
# Required by Elasticsearch 5.0 and later
vm.max_map_count=262144
# enable forwarding so the Docker networking works as expected
net.ipv4.ip_forward=1
# Decrease the maximum number of TCP retransmissions to 5 as recommended for Elasticsearch TCP retransmission timeout.
# See https://www.elastic.co/guide/en/elasticsearch/reference/current/system-config-tcpretries.html
net.ipv4.tcp_retries2=5
# Make sure the host doesn't swap too early
vm.swappiness=1
EOF

Apply the new sysctl settings

sudo sysctl -p
sudo systemctl restart NetworkManager

As a sudoers user, adjust the system limits. Add the following configuration values to the /etc/security/limits.conf file.

*                soft    nofile         1024000
*                hard    nofile         1024000
*                soft    memlock        unlimited
*                hard    memlock        unlimited
elastic          soft    nofile         1024000
elastic          hard    nofile         1024000
elastic          soft    memlock        unlimited
elastic          hard    memlock        unlimited
elastic          soft    nproc          unlimited
elastic          hard    nproc          unlimited
root             soft    nofile         1024000
root             hard    nofile         1024000
root             soft    memlock        unlimited

NOTE: This step is optional if the docker registry doesn’t require authentication.

Authenticate the elastic user to pull images from the docker registry you use, by creating the file /home/elastic/.docker/config.json. This file needs to be owned by the elastic user. If you are using a user name other than elastic, adjust the path accordingly.

Example: In case you use docker.elastic.co, the file content looks like as follows:

{
 "auths": {
   "docker.elastic.co": {
     "auth": "<auth-token>"
   }
 }
}

Restart the podman service by running this command:

sudo systemctl daemon-reload
sudo systemctl restart podman

Reboot the RHEL host

sudo reboot